Biomaterial Database

Role of type 1 and type 3 fimbriae in Klebsiella pneumoniae biofilm formation. 2010

Casper Schroll, and Kim B Barken, and Karen A Krogfelt, and Carsten Struve

Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen S, Denmark.

BACKGROUND Klebsiella pneumoniae is an important gram-negative opportunistic pathogen causing primarily urinary tract infections, respiratory infections, and bacteraemia. The ability of bacteria to form biofilms on medical devices, e.g. catheters, has a major role in development of many nosocomial infections. Most clinical K. pneumoniae isolates express two types of fimbrial adhesins, type 1 fimbriae and type 3 fimbriae. In this study, we characterized the role of type 1 and type 3 fimbriae in K. pneumoniae biofilm formation. RESULTS Isogenic fimbriae mutants of the clinical K. pneumoniae isolate C3091 were constructed, and their ability to form biofilm was investigated in a flow cell system by confocal scanning laser microscopy. The wild type strain was found to form characteristic biofilm and development of K. pneumoniae biofilm occurred primarily by clonal growth, not by recruitment of planktonic cells. Type 1 fimbriae did not influence biofilm formation and the expression of type 1 fimbriae was found to be down-regulated in biofilm forming cells. In contrast, expression of type 3 fimbriae was found to strongly promote biofilm formation. CONCLUSIONS By use of well defined isogenic mutants we found that type 3 fimbriae, but not type 1 fimbriae, strongly promote biofilm formation in K. pneumoniae C3091. As the vast majority of clinical K. pneumoniae isolates express type 3 fimbriae, this fimbrial adhesin may play a significant role in development of catheter associated K. pneumoniae infections.

UI	MeSH Term	Description	Entries
D007711	Klebsiella pneumoniae	Gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.	Bacillus pneumoniae,Bacterium pneumoniae crouposae,Hyalococcus pneumoniae,Klebsiella pneumoniae aerogenes,Klebsiella rhinoscleromatis
D010861	Fimbriae, Bacterial	Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).	Bacterial Fimbriae,Bacterial Pili,Common Fimbriae,Common Pili,Pili, Bacterial,Pili, Common,Bacterial Fimbria,Bacterial Pilus,Common Fimbria,Common Pilus,Fimbria, Bacterial,Pilus, Bacterial,Fimbria, Common,Fimbriae, Common,Pilus, Common
D015964	Gene Expression Regulation, Bacterial	Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.	Bacterial Gene Expression Regulation,Regulation of Gene Expression, Bacterial,Regulation, Gene Expression, Bacterial
D018441	Biofilms	Encrustations formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedded in an EXTRACELLULAR POLYMERIC SUBSTANCE MATRIX that is secreted by the microbes. They occur on body surfaces such as teeth (DENTAL DEPOSITS); inanimate objects, and bodies of water. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and anti-fouling agents.	Biofilm
D018829	Adhesins, Bacterial	Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.	Adhesins, Fimbrial,Bacterial Adhesins,Fimbrial Adhesins,Adhesin, Bacterial,Bacterial Adhesin